Mangahao Power Station is a hydroelectric power station near the town of Shannon, New Zealand. After being delayed by war, access roading and foundation testing was started by late 1919 and the station opened in November 1924. It makes use of Mangahao River, through a series of tunnels and pipelines totaling 4.8 kilometers, in the Tararua Ranges. Mangahao Power Station became the power station for Wellington, Horowhenua, Taranaki, Hawkes Bay, and the Wairarapa. As of 2012, it is jointly owned and operated by Todd Energy and King Country Energy.
It is one of the oldest large power stations in New Zealand.
Martin, John E, ed. (1991). People, Power and Power Stations: Electric Power Generation in New Zealand 1880 - 1990. Wellington: Bridget Williams Books Ltd and Electricity Corporation of New Zealand. pp. 316 pages. ISBN0-908912-16-1.
Reilly, Helen (2008). Connecting the Country: New Zealand’s National Grid 1886 - 2007. Wellington: Steele Roberts. pp. 376 pages. ISBN978-1-877448-40-9.